Module# 05: Linked List Lecture#20: Linked List with JCF

// Example 20.1: Create a linked list

// This program define a linked list and add some items into it.

import java.util.*;

public class CreateLLandAddItems {

public static void main(String args[]) {

// Creating an empty ll of class LinkedList

LinkedList<String>ll = new LinkedList<String>();

// Adding elements to the linked list using a number of add methods

ll.add("Mumbai");

ll.add("Chennai");

ll.add("Kolkata");

ll.add("Delhi");

ll.add("Bangalore");

ll.add("Guwahati");

ll.add("Hyderabad");

// System.out.println("Linked list : "+ ll); // Simple printing

// Printing the list using an iterator

Iterator<String>itr=ll.iterator();

while(itr.hasNext()){

System.out.println(itr.next());

}

}

}

// Example 20.2: Create a linked list with user defined objects

/* This program shows how to create an array of objects of type Students and then add the array into a linked list and then printing the same. */

import java.util.*;

//Declaration of a user defined class

class Student {

String name;

double marks;

// Constructor

Student(String s, double m) {

name = s;

marks = m;

}

void printData () {// To parant a reacord

System.out.print("Name : " + name);

System.out.println(" Marks : " + marks);

}

}

// The main class is defined below.

public class CreateLLofCollection {

public static void main(String args[]) {

// Create an aaray of objects

Student sArray[] = new Student[5]; // To store 5 objects

// Create the array sArray

sArray[0] = new Student("Ram", 79.6);

sArray[1] = new Student("Rahim", 85.5);

sArray[2] = new Student("John", 90.1);

sArray[3] = new Student("Lisa", 69.4);

sArray[4] = new Student("Ana", 59.8);

// Creating a linked-list with sArray collection

LinkedList<Student> ll = new LinkedList<Student>(Arrays.asList(sArray));

Student temp;

// Printing the list using an iterator

Iterator<Student>itr=ll.iterator();

while(itr.hasNext()){

temp = itr.next();

temp.printData(); // Print the current record.

}

}

}

// Example 20.3: Insertion at different locations

/*This program shows how items can be inserted at different locations in a linked list. For this purpose, there are methods like add(), addFirst(), addLast() are defined in the LinkedList class. */

import java.util.*;

public class LLinsertionDemo {

public static void main(String args[]) {

// Creating an empty ll of class LinkedList

LinkedList<String>ll = new LinkedList<String>();

// Adding elements to the linked list using a number of add methods

ll.add("Mumbai"); // Add an initial item

ll.add("Chennai"); // Add another item

ll.addLast("Kolkata"); // Add at the end

ll.addFirst("Delhi"); // Add at the front

ll.add(2, "Bangalore"); // Add in the specific location

ll.add("Guwahati"); // Sequential add goes at the end

ll.add("Hyderabad"); // Another sequential insertion

// Printing the list using an iterator

Iterator<String>itr=ll.iterator();

while(itr.hasNext()){

System.out.println(itr.next());

}

// Alternatively:

System.out.println("Linked list : "+ ll); // Simple printing

}

}

// Example 20.4: Insertion of a list into a LinkedList

/* A sub list can be inserted into a linked list in addition to a single item. This program shows how a sub list can be inserted at different locations in a linked list. For this purpose, the addAll() method is used.*/

import java.util.*;

public class InsertSubListToLL{

public static void main(String args[]){

LinkedList<String> ll1 = new LinkedList<String>();

System.out.println("Initial list of elements: "+ ll1);

ll1.add("MP Allahabad");

ll1.add("MP Lucknow");

ll1.add("MP Varanasi");

System.out.println("Initial list: ” + ll1);

// Create another linked list, say ll2

LinkedList<String> ll2 = new LinkedList<String>();

ll2.add("MLA Nadia");

ll2.add("MLA Kharagpur");

//Adding the second list (ll2) to the first list (ll1)

ll1.addAll(ll2);

System.out.println("After adding ll2 to ll1: ” + ll1);

// Create another linked list, say ll3

LinkedList<String> ll3 = new LinkedList<String>();

ll3.add("MLA Durgapur");

ll3.add("MLA Howrah");

//Inserrt ll3 at a specific position of ll1

ll1.addAll(3, ll3); // Insert ll3 at location 3 of ll1

System.out.println("After insetting ll3: ” + ll1);

//Do some normal insertions

ll1.addFirst("President");

ll1.addLast("Prime Minister");

ll1.add("MP Chennai");

System.out.println("The final list ” + ll1);

}

}

// Example 20.5: Deletion of an object from a LinkedList

/* Like insertion, deletion operation on a linked list can be carried our many ways. Following few examples illustrates the deletion operation with methods remove(), removeFirst(), removeLast(), etc.*/

import java.util.*;

public class DeletionFromLL {

public static void main(String [] args) {

// Creating a linked list

LinkedList<String>ll1 = new LinkedList<String>();

ll1.add("A");

ll1.add("E");

ll1.add("I");

ll1.add("O");

ll1.add("U");

ll1.add("H");

System.out.println("List of vowels: "+ll1);

//Removing specific element from the linked list

ll1.remove("H"); // Rmovee the vowel H

System.out.println("After deletion of H : "+ll1);

//Removing element on the basis of specific position

ll1.remove(0); // This will remove A from the list

System.out.println("After invoking remove(index) method: "+ll1);

// Let’s create another list of semi-vowels

LinkedList<String> ll2=new LinkedList<String>();

ll2.add("M");

ll2.add("N");

// Adding new elements to the list of vowels

ll1.addAll(ll2); // Append ll2 after ll1

System.out.println("Updated list : "+ll1);

//Removing first element from the list

ll1.removeFirst();

System.out.println("After invoking removeFirst() method: "+ll1);

//Removing last element from the list

ll1.removeLast();

System.out.println("After invoking removeLast() method: "+ll1);

// Removing all elements from ll2

ll1.removeAll(ll2);

System.out.println("After removing semi-vowels: "+ll1);

ll1.add("A");

ll1.add("B");

ll1.add("A");

//Removing first occurrence of element from the list

ll1.removeFirstOccurrence("A");

System.out.println("After removing first occurrence of A: "+ll1);

//Removing the last occurrence of B

ll1.removeLastOccurrence("B");

System.out.println("After invoking removeLastOccurrence() method: "+ll1);

//Removing all the elements present in the list

ll1.clear();

System.out.println("After invoking clear() method: "+ll1);

}

}

// Example 20.6: Traversal operation on a linked List collection

/* The following program illustrates how to traverse two different type of lists in reverse order, that is, from the end to the front. */

import java.util.*;

public class TravserseReverseLL{

public static void main(String args[]){

// Case 1: a linked list of countries

LinkedList<String> lCountries = new LinkedList<String>();

lCountries.add("Australia");

lCountries.add("India");

lCountries.add("South Africa");

lCountries.add("Zimbabwe");

//Traversing the list of countries in reverse order

Iterator itr1 =lCountries.descendingIterator();

while(itr1.hasNext()) {

System.out.println(itr1.next());

}

// Case 2: a linked list of numbers

LinkedList<Integer> lNumbers = new LinkedList<Integer>();

lNumbers.add(123);

lNumbers.add(345);

lNumbers.add(567);

lNumbers.add(789);

//Traversing the list of numbers in reverse order

Iterator itr2 = lNumbers.descendingIterator();

while(itr2.hasNext()) {

System.out.println(itr2.next());

}

}

}

// Example 20.7: Miscellaneous operations

/* The LinkedList class is loaded with several other methods like get(), contain(), size(), set(), etc. The following program illustrates those methods and their utilities in Java programming. */

import java.util.*;

public class OtherMethodsOfLL{

public static void main(String args[]){// Creating a linked list

LinkedList<String>lLetters = new LinkedList<String>();

lLetters.add("J");

lLetters.add("O");

lLetters.add("Y");

lLetters.add("W");

lLetters.add("I");

lLetters.add("T");

lLetters.add("H");

lLetters.add("J");

lLetters.add("A");

lLetters.add("V");

lLetters.add("A");

lLetters.add("2020");

System.out.println("List : "+lLetters);

// Finding an elements in the linked list

boolean status = lLetters.contains("Z");

if(status)

System.out.println("List contains the element 'Z' ");

else

System.out.println("List doesn't contain 'Z'");

// Finding the number of elements in the linked list

int size = lLetters.size();

System.out.println("Number of letters = "+ size);

// Get and set elements from the linked list

String element = lLetters.get(11);

System.out.println("Element returned by get() : ” + element);

lLetters.set(11, "The fun");

System.out.println("Linked list after change : ” + lLetters);

}

}

// Example 20.8: Case study with a user defined objects

/* The following, a program shows a list a number of books, insertion of another books in the list, deletion of books and then traversing of the books, etc.*/

import java.util.*;

// Defining a calls Book

class Book {

int accnNo;

String title, author, publisher;

double cost;

// Constructor of the class

Book(int id, String t, String auth, String pub, double val) {

accnNo = id;

title = t;

author = auth;

publisher = pub;

cost = val;

}

}

// The main class maintaining a library of books

public class LibraryLL {

public static void main(String[] args) {

List<Book> library =new LinkedList<Book>(); //Creating list of Books

//Creating a list of Books

Book b1 = new Book(101,"Oracle Java","Leslie Lamport","Oxford",88.5);

Book b2 = new Book(102,"Complete Java","McGraw Hill", "TMH" , 94);

Book b3 = new Book(103,"Joy with Java","Samanta","Prentice Hall",69.6);

library.add(b1); //Adding books to list

library.add(b2);

library.add(b3);

//Traversing the list

for(Book b:library){System.out.println("Book ID: " +b.accnNo);

System.out.print(b.title+" "+b.author+" "+b.publisher+" "+b.cost);

System.out.println();

}

}

}